The triangle bruxism, pain, and psychosocial factors

The triangle bruxism, pain, and psychosocial factors

Daniele Manfredini

This thesis was prepared at the Department of Oral Function and Restorative Dentistry, section Oral Kinesiology, of the Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, and the Vrije Universiteit, Research Institute MOVE, Amsterdam, the Netherlands

Copyright: Daniele Manfredini, 2011 ISBN/EAN: 978-90-902-6384-7

The triangle bruxism, pain, and psychosocial factors

ACADEMISCH PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit van Amsterdam op gezag van de Rector Magnificus prof. dr. D.C. van den Boom ten overstaan van een door het college voor promoties ingestelde commissie, in het openbaar te verdedigen in de Agnietenkapel op vrijdag 9 december 2011, te 10:00 uur

door Daniele Manfredini geboren te Carrara, Italië

Promotiecommissie Promotor:

Prof. dr. F. Lobbezoo

Co-promotoren:

Dr. E. Winocur Dr. J. Ahlberg

Overige leden:

Prof. dr. A. De Laat Prof. dr. A. de Jongh Prof. dr. J. de Lange Prof. dr. ir. M. Naeije Prof. dr. M.A.J. van Waas

Faculteit der Tandheelkunde

“To keep a lamp burning we have to keep putting oil in it.” Mother Teresa of Calcutta

To Debora To Aurora and Giacomo To my parents

Contents

Chapter 1

Introduction

11

Chapter 2

Relationship between bruxism and temporomandibular disorders. A systematic review of literature from 1998 to 2008

19

Chapter 3

Self-reported bruxism and temporomandibular disorders. Findings from two specialized centers

63

Chapter 4

Role of psychosocial factors in the etiology of bruxism

79

Chapter 5

Influence of psychological symptoms on home-recorded sleep-time masticatory muscles activity in healthy subjects

107

Chapter 6

Psychosocial impairment in temporomandibular disorders patients. RDC/TMD axis II findings from a multicenter study

129

Chapter 7

Correlation of RDC/TMD axis I diagnoses and axis II painrelated disability. A multicenter study

147

Chapter 8

General discussion

165

Chapter 9

Summary

181

Samenvatting

187

Riassunto

195

Curriculum vitae

201

List of publications

202

Acknowledgements

210

9

10

Chapter 1

INTRODUCTION

11

D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

Temporomandibular disorders (TMD) are a heterogeneous group of pathologies affecting the jaw muscles, the temporomandibular joints (TMJ), or both 1. The main signs and symptoms characterizing the clinical manifestation of TMD are represented by joint sounds, functional limitation, and pain 2. Of these, pain is by far the main reason for patients to ask for advice and treatment, thus being the main target for diagnosis and treatment 3. Over the years, a number of etiological theories were proposed to explain the pathophysiology of TMD, and the paradigm concept characterizing TMD practice initially focused on dental occlusion. For decades, the search for supposed abnormalities in teeth alignment and interarch relationship has been the main, not to say the unique, approach to the study of TMD etiology, and their correction was advocated as a necessary causal treatment for TMD symptoms 4. More recently, evidence-based literature dismantled the validity of the occlusal paradigm 5. The search for alternative hypotheses for the pathophysiology of TMD and for customized treatment algorithms, which began already in the ‘50s of the past century, received a strong input from investigations performed over the past two decades 6. Amongst others, it became clear that psychosocial aspects of the disease, viz., concurrent depression, anxiety, stress, and pain-related disability, have a strong influence on an individual’s quality of life and on treatment outcome 7-9. This led to current views on TMD as a group of multifactorial disorders to be assessed within a biopsychosocial context. Bruxism is a motor muscle activity characterized by teeth grinding and/or jaw clenching during sleep and/or wake time 10. It is considered a risk factor for damage to the stomatognathic structures, and it was called into cause as a potential cause for both muscle and joint overload 11,12. Pain in the jaw muscles and in the TMJ has thus been indicated as a consequence of bruxism, and sometimes pain has been proposed to be assessed as a bruxism symptom as well. However, the literature is not conclusive on the actual causeand-effect relationship between bruxism and pain

13,14

. Actually, uncertainties on this issue

may be explained by the very definition of bruxism itself, which suggests that it is a complex clinical entity including different jaw muscles motor activities, viz., clenching and grinding, performed at different stages of the circadian rhythm, viz., sleeping and

12

Chapter 1 – General introduction

wakefulness 15-17. In view of these considerations, it is plausible that getting deeper into the knowledge of the etiology and pathophysiology of the different bruxism activities will help comprehending better its complex relationship with TMD pain. As in the case of the TMD literature, works on the etiology of bruxism suggested that peripheral sensory influences play only a minor role in the pathogenesis

18

, while

factors related to the central nervous system (CNS) seem to have much more importance 19,20

. From an etiological viewpoint, there are some suggestions that psychosocial factors

may play a role in the etiology of bruxism, thus constituting a possible common denominator with pain referred by TMD patients 21,22. Briefly, bruxism has been associated with emotional tension, psychosomatic disorders, hostility, aggressiveness, apprehension and a tendency to worrying, and also to psychiatric disorders such as schizophrenia

23-25

number of psychiatric and psychosocial disorders

. TMD pain is also associated with a 26,27

, mainly relating to anxiety disorders

in the acute stage of pain and depression disorders in the chronic phase 28. In addition, the association between pain and psychosocial factors depends only in part on the pain location 29

. TMD pain may be associated with bruxism as well, so the study of bruxism in this

context is complicated by the relationships that both bruxism and pain have with psychosocial factors, to the point that there are some preliminary suggestions for a different psychosocial profile of bruxers with and without chronic facial pain 30. From the above, it is clear that bruxism, TMD pain, and psychosocial factors form a “triangle” of interconnected disorders, and their mutual relationships are likely to reciprocally influence each other and have a strong impact on the TMD clinics. Getting deeper into the study of such triangle may provide some basis to construct evidence in support of new paradigmatic concepts on which TMD practice should be based. The general aim of the present thesis was to obtain a deeper insight into the mutual interactions between the three components of the triangle. Specific research questions and aims will be formulated for each chapter of this thesis. The starting point of the project was a systematic literature review performed to assess the relationship between bruxism and temporomandibular disorders. The review,

13

D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

described in Chapter 2 of this thesis, aimed to summarize and update all the available information with respect to the last comprehensive review on the argument, which dated back to more than a decade ago 13. For that reason, the literature published later than 1998 was selected, and findings were interpreted as the basis to discuss data from a series of multicenter investigations involving four highly specialized university centers for TMD treatment (Amsterdam, Padova, Tel Aviv, and Helsinki). The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) 31

are a standardized diagnostic system adopted to favour multicenter data gathering and

comparison, and they were widely used over the years to collect data on patient and nonpatient populations in several countries. In Chapter 3 of this thesis, the association between self-reported bruxism, as diagnosed with the RDC/TMD history taking questionnaire, and the different TMD diagnostic groups, as diagnosed with the RDC/TMD axis I examination guidelines, was assessed. The discussion was focused on a comparison with findings from the literature and on the attempt to suggest a rationale to explain the peculiarities of the bruxism-TMD association in the clinical setting. As a next step in further elucidating the triangle bruxism, pain, and psychosocial factors, a systematic review of the literature on the association between bruxism and psychosocial factors was performed. Findings of this review, described in Chapter 4 of this thesis, allowed hypothesizing on the existence of a common psychosocial denominator for some TMD-related painful disorders and some bruxism activities. As a consequence, with the aim to further improve knowledge on the role of psychosocial factors in the etiology of bruxism, sleep-time masticatory muscles activities were recorded in a home environment in a group of healthy volunteers completing a set of questionnaires to rate their anxiety and depression symptoms. The study protocol and the results of this study are described in Chapter 5 of this thesis. Finally, the studies described in Chapters 6 and 7 of this thesis examined the remaining side of the triangle, i.e., the associations between TMD pain and psychosocial factors, by investigating the prevalence of depression and somatization and the rate of chronic pain-related disability in patients with TMD pain. Multicenter designs were adopted in both chapters, the former describing findings gathered with the RDC/TMD axis

14

Chapter 1 – General introduction

II for psychosocial assessment in TMD patients and the latter correlating such findings with those gathered with the RDC/TMD axis I for physical diagnosis in both patient and nonpatient populations.

Synopsis The topic of this thesis is the relationship between bruxism, pain, and psychosocial factors. Several aspects of the mutual interactions between the three components of the triangle will be studied. The aims of the thesis are the following: (1) to systematically review the literature on bruxism, with focus on its relationship with temporomandibular disorders and on the role of psychosocial factors in bruxism’s etiology (Chapters 2 and 4); (2)

to

investigate

for

the

relationship

between

self-reported

bruxism

and

temporomandibular disorders (Chapter 3); (3) to study the influence of psychological symptoms on sleep-time masticatory muscles activity (Chapter 5); and (4) to assess the psychosocial impairment of TMD patients and its relationship with the physical diagnoses (Chapters 6 and 7).

References 1.

McNeill C. History and evolution of TMD concepts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997; 83: 51-60.

2.

Laskin DM. Etiology of the pain-dysfunction syndrome. J Am Dent Assoc 1969; 79:147-153.

3.

Manfredini D. Fundamentals of TMD management. In: Manfredini D (Ed). Current concepts on temporomandibular disorders. Berlin, Quintessence Publishing 2010: 305-318.

4.

McNeill C. Management of temporomandibular disorders: concepts and controversies. J Prosthet Dent 1997; 77: 510-22.

5.

Koh H, Robinson PG. Occlusal adjustment for treating and preventing temporomandibular joint disorders. J Oral Rehabil 2004; 31: 287-292.

6.

Greene C. Concepts of TMD etiology: effects on diagnosis and treatment. In: Laskin DM, Greene CS, Hylander WL (Eds). TMDs. An evidence-based approach to diagnosis and treatment. Chicago, Quintessence Publishing 2006: 219-228.

7.

Rollmann GB, Gillespie JM. The role of psychosocial factors in temporomandibular disorders. Curr Rev Pain 2000; 4: 71-81.

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D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

8.

Dworkin SF, Sherman J, Mancl L, Ohrbach R, LeResche L, Truelove E. Reliability, validity, and clinical utility of the research diagnostic criteria for temporomandibular disorders axis II scales: depression, nonspecific physical symptoms, and graded chronic pain. J Orofac Pain 2002; 16: 207–20.

9.

Türp JC, Jokstad A, Motschall E, Schindler HJ, Windecker-Getaz I, Ettlin DA. Is there a superiority of multimodal as opposed to simple therapy in patients with temporomandibular disorders? A qualitative systematic review of literature. Clin Oral Implants Res 2007; 18 Suppl. 3: 138-150.

10.

De Leeuw R (Ed). The American Academy of Orofacial Pain. Orofacial pain: guidelines for assessment, diagnosis, and management. Chicago, Quintessence Publishing, 2008.

11.

Molina OF, Dos Santos Jr J, Nelson SJ, Nowlin T. A clinical study of specific signs and symptoms of CMD in bruxers classified by the degree of severity. Cranio 1999; 17: 268-279.

12.

Manfredini D, Cantini E, Romagnoli M, Bosco M. Prevalence of bruxism in patients with different research diagnostic criteria for temporomandibular disorders (RDC/TMD) diagnoses. Cranio 2003; 21: 279-85.

13.

Lobbezoo F, Lavigne GJ. Do bruxism and temporomandibular disorders have a cause-and-effect relationship? J Orofac Pain 1997; 11: 15-23.

14.

Svensson P, Jadidi F, Arima T, Baad-Hansen L, Sessle BJ. Relationships between craniofacial pain and bruxism. J Oral Rehabil 2008; 35: 524-47.

15.

Macaluso GM, Guerra P, Di Giovanni G, Boselli M, Parrino L, Terzano MG. Sleep bruxism is a disorder related to periodic arousal during sleep. J Dent Res 1998; 77: 565-73.

16.

De Laat A, Macaluso GM. Sleep bruxism is a motor disorder. Mov Disord 2002; 17 Suppl 2: S67-S69.

17.

Paesani DA. Introduction to bruxism. In: Paesani DA (Ed). Bruxism. Theory and practice. Berlin, Quintessence Publishing 2010: 3-20.

18.

Kato T, Thie NM, Huyhn N, Miyawaki S, Lavigne GJ. Topical review: sleep bruxism and the role of peripheral sensory influences. J Orofac Pain 2003; 17: 191-213.

19.

Lobbezoo F, Naeije M. Bruxism is mainly regulated centrally, not peripherally. J Oral Rehabil 2001; 28: 1085-91.

20.

Lobbezoo F, Hamburger HL, Naeije M. Etiology of bruxism. In: Paesani DA (Ed). Bruxism. Theory and practice. Berlin, Quintessence Publishing 2010: 53-66.

21.

Van Selms MKA, Lobbezoo F, Wicks DJ, Hamburger HL, Naeije M. Craniomandibular pain, oral parafunctions, and psychological stress in a longitudinal case study. J Oral Rehabil 2004; 31: 738-45.

22.

Manfredini D, Landi N, Fantoni F, Segù M, Bosco M. Anxiety symptoms in clinically diagnosed bruxers. J Oral Rehabil 2005; 32: 584-8.

23.

Kampe T, Edman G, Bader G, Tagdae T, Karlsson S. Personality traits in a group of subjects with longstanding bruxing behaviour. J Oral Rehabil. 1997; 24:588–593.

24.

Molina OF, dos Santos J. Hostility in TMD/bruxism patients and controls: a clinical comparison study and preliminary results. Cranio 2002; 20: 282-288.

16

Chapter 1 – General introduction

25.

Winocur E, Hermesh H, Littner D, Shiloh R, Peleg L, Eli I. Signs of bruxism and temporomandibular disorders among psychiatric patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007; 103: 6063.

26.

Yap AJU, Dworkin SF, Chua EK, List T, Tan KBC, Tan HH. Prevalence of temporomandibular disorders subtypes, psychologic distress and psychosocial dysfunction in Asian patients. J Orofac Pain 2003; 17: 21-8.

27.

Manfredini D, Marini M, Pavan C, Pavan L, Guarda-Nardini L. Psychosocial profiles of painful temporomandibular disorders. J Oral Rehabil 2009; 36: 193-198.

28.

Gatchel RJ, Garofalo JP, Ellis E, Holt M. Major psychological disorders in acute and chronic TMD: an initial examination. J Am Dent Assoc 1996; 127: 1365-1374.

29.

Manfredini D, Bandettini di Poggio A, Romagnoli M, Dell'Osso L, Bosco M. Mood spectrum in patients with different painful temporomandibular disorders. Cranio 2004; 22: 234-240.

30.

Camparis CM, Siqueira JT. Sleep bruxism: clinical aspects and characteristics in patients with and without chronic orofacial pain. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006; 101: 188-193.

31.

Dworkin SF, LeResche L. Research diagnostic criteria for temporomandibular disorders: Review, criteria examinations and specifications, critique. J Craniomandib Disord Fac Oral Pain 1992; 6: 301-355.

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D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

18

Chapter 2

RELATIONSHIP BETWEEN BRUXISM AND TEMPOROMANDIBULAR DISORDERS. A SYSTEMATIC REVIEW OF LITERATURE FROM 1998 TO 2008

Daniele Manfredini, Frank Lobbezoo

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics 2010; 109:e26-e50

19

D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

Abstract Objectives The present paper aims to systematically review the literature on the temporomandibular disorders (TMD)-bruxism relationship published from 1998 to 2008. Study design A systematic search in the National Library of Medicine’s PubMed database was performed to identify all studies on humans assessing the relationship between TMD symptoms and bruxism diagnosed with any different approach. The selected articles were assessed independently by the 2 authors according to a structured reading of articles format (PICO). Results A total of 46 articles were included for discussion in the review and grouped into questionnaire/self-report (n = 21), clinical assessment (n = 7), experimental (n = 7), tooth wear (n = 5), polysomnographic (n = 4), or electromyographic (n = 2) studies. In several studies, the level of evidence was negatively influenced by a low level of specificity for the assessment of the bruxism-TMD relationship, because of the low prevalence of severe TMD patients in the studied samples and because of the use of self-report diagnosis of bruxism with some potential diagnostic bias. Conclusions Investigations based on self-report or clinical bruxism diagnosis showed a positive association with TMD pain, but they are characterized by some potential bias and confounders at the diagnostic level (e.g., pain as a criterion for bruxism diagnosis). Studies based on more quantitative and specific methods to diagnose bruxism showed much lower association with TMD symptoms. Anterior tooth wear was not found to be a major risk factor for TMD. Experimental sustained jaw clenching may provoke acute muscle tenderness, but it is not analogous to myogenous TMD pain, so such studies may not help clarify the clinical relationship between bruxism and TMD.

20

Chapter 2 – Bruxism and TMD systematic review

Introduction The study of bruxism is complicated by some taxonomic and diagnostic aspects, which have prevented achieving an acceptable standardization of diagnosis until the recent years. Indeed, a major concern for researchers approaching this phenomenon is the definition of bruxism itself, which is a term grouping different entities, viz., sleep and awake bruxism 1. The American Academy of Sleep Medicine defines bruxism as a stereotyped oral motor disorder characterized by sleep-related grinding and/or clenching of the teeth 2, while the American Academy of Orofacial Pain extends the definition to the same movements which occur during wakefulness 3. There is a considerable amount of literature suggesting that sleep and awake bruxism are two different disorders with a different etiopathogenesis

4-11

. Sleep bruxism is

characterized by both a grinding-type and a clenching-type activity and is associated with complex micro-arousal phenomena occurring during sleep, the pathophysiology of which is yet to be clarified

7,12-14

, while awake bruxism is characterized by a clenching-type activity

and is associated with psychosocial factors and a number of psychopathological symptoms 11

. Due to their different characteristics, sleep and awake bruxism may have different

consequences on the masticatory muscles and the temporomandibular joints. This issue is an under-reviewed aspect in the literature. Indeed, although bruxism is commonly considered the most detrimental among all the parafunctional activities of the stomatognathic system and a major risk factor for temporomandibular disorders (TMD), there are still many unsolved issues concerning the actual causal relationship between the occurrence of TMD symptoms and bruxism 15,16. In particular, there is a need to clarify the possibly differential role of both types of bruxism in the etiology of TMD. The issue is complicated by the difficulties to distinguish clinically between sleep and awake bruxism, as well as by the unclear distinction between instrumentally detected bruxism on the one hand and clinically diagnosed or self-perceived bruxism on the other hand

17

. Sleep bruxism (SB) as a pathophysiological entity can only be detected

unequivocally by means of polysomnographic recordings, the employ of which is limited by the high costs and the low number of adequately equipped sleep laboratories

21

18

.

D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

Nonetheless, even though clinical or self-report (viz., questionnaires, interviews) approaches to bruxism diagnosis still remain incomplete, not allowing a distinction between the different types of this disorder, they are the easiest and most adopted methods to gather data in large-sample studies. All these difficulties may have discouraged researchers to perform investigations to get deeper into the assessment of the bruxism-TMD relation, and the paucity of welldesigned works led the authors of the last comprehensive review on this issue to conclude that there were not enough elements to support or refute the existence of a causal link between bruxism and TMD 15. It should be interesting to assess whether knowledge on the TMD-bruxism relation is improved with respect to data available at the time of that review. Considering these premises, the present paper aims to systematically review the literature on the TMD-bruxism relationship over the last decade and, when possible, to discuss available information on the different types of bruxism.

Materials and methods On May 26th, 2009, a systematic search in the National Library of Medicine’s PubMed Database was performed to identify all peer-review papers in the English literature dealing with the bruxism-TMD relation according to the search strategy described below. The studies included for review were assessed independently by the two authors on the basis of a structured reading of articles approach which is also described in details in the following sections. Search strategy and literature selection A search with Medical Subjects Headings (MeSH) terms was first used, and the following terms were used to identify a list of potential papers to be included in the review: -

Temporomandibular joint disorders: A variety of conditions affecting the anatomic and functional characteristics of the temporomandibular joint. Factors contributing to the complexity of temporomandibular diseases are its relation to dentition and mastication and the symptomatic effects in other areas which account for referred pain to the joint and the difficulties in applying traditional diagnostic procedures to temporomandibular joint

22

Chapter 2 – Bruxism and TMD systematic review

pathology where tissue is rarely obtained and x-rays are often inadequate or nonspecific. Common diseases are developmental abnormalities, trauma, subluxation, arthritis, and neoplasia. Year introduced: 1997 (Previous indexing: temporomandibular joint diseases 1982-1996). -

Bruxism: A disorder characterized by grinding and clenching of the teeth. Year introduced: 1965.

The search was limited to papers on adult populations (+19 years) in the English language published later than 01/01/1998. The combination of the two MeSH terms, which alone yielded 11975 and 1932 citations, respectively, allowed identifying 127 citations, the abstracts of which were read to select articles to be retrieved in full-text. The inclusion criteria for admittance in the systematic review were based on the type of study, viz., clinical studies on humans, assessing: 1. the relation between TMD symptoms and bruxism diagnosed clinically or by means of questionnaires/interviews; 2. the relation between TMD symptoms and bruxism diagnosed by means of polysomnography (PSG) or electromyography (EMG); or 3. the effects of experimental clenching or grinding on the onset of TMD symptoms. In cases of duplication studies (i.e. studies presenting the same findings and/or conducted on the same populations), only one paper was included for further assessment. After abstracts reading, 78 papers were excluded from further assessment, and the remaining 49 papers were retrieved in full text and assessed for possible admittance in the review. The full texts were assessed independently by the two authors and consensus was reached in all cases to include/exclude papers from systematic assessment. Also, the PubMed search was expanded to the articles related to the selected ones and the reference lists of the full-text papers were read carefully to search for other studies to be potentially included in the review. Systematic assessment of papers The methodological characteristics of the selected papers were assessed according to a format which enabled a structured summary of the articles in relation to four main issues, viz., patients/problem/population, intervention, comparison, and outcome (PICO), for each of which specific questions were constructed.

23

D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

For each article, the study population (‘P’) was described in the light of the criteria for inclusion, the demographic features of the sample, and the sample size. The study design was described in the section reserved to questions on the study intervention (‘I’), and information was gathered on all methodological features of the study, viz., longitudinal or cross-sectional-observational design, type of experiment/intervention protocol, blindness of the examiners, assessment instruments, and statistical analysis. The comparison criterion (‘C’) assessed the presence of any comparison groups, viz., a control group or a specific comparison subgroup within the patients’ population. The study outcome (‘O’) was evaluated on the basis of the application of objective diagnostic criteria for bruxism as well as for TMD, calibration of operators/diagnosis, features of the described association (strength, dose/response, temporality, biological plausibility), and the authors’ conclusions consistency with study findings. Also, the authors’ main conclusions with regards to the bruxism-TMD association were reported. All the above-described features of the included studies were put into tables, which also comprehend some critical considerations about the potential points of strength and weakness. All the studies were assessed separately by the two authors, and in cases of divergent assessments with regards to the assignment of strengths and weaknesses, the element under discussion was deleted from the tables if consensus wasn’t reached.

Results After examination of the full-text articles, 33 papers were selected for inclusion in the review. From the reference lists of the included papers and PubMed-related articles, another 17 potentially relevant titles were identified and also retrieved as full texts. Four of them were subsequently excluded for not fulfilling the inclusion criteria, and 13 papers were added to the original list of papers, thus accounting for a total of 46 papers to be discussed in the review. Table 2.1 provides the list of papers excluded after reading the full texts, including the reason for exclusion. According to the criteria adopted to make the diagnosis of bruxism, the papers included in the review were grouped into questionnaire/self-report (N=21), clinical

24

Chapter 2 – Bruxism and TMD systematic review

assessment (N=7), experimental (N=7), tooth wear (N=5), polysomnographic (N=4) or electromyographic (N=2) studies. Table 2.1. Studies retrieved in full text and excluded from the review. Study’ s first author and year Mundt, 2008 19 Johansson, 2008 21 Park, 2008 22 Rues, 2008 23 Leresche, 2007 24 Pizolato, 2007 25 Unell, 2006 26 Casanova- Rosado, 2006 27 Glaros, 2005 28 Johansson, 2004 30 Carlsson, 2004 33 Johansson, 2003 31 Carlsson, 2002 35 Molina, 2001 36 Amemori, 2001 37 Egermark, 2001 38 Magnusson, 2000 39 Molina, 2000 40 Gavish, 2000 41 Kieser, 1998 42

Reason for exclusion Same data presented in 20 Longitudinal study on bruxism and TMD prevalence Assessment of tooth grinding pattern Activity of jaw muscles during different clenching levels Study on adolescents only Maximal bite force in TMD and bruxism Longitudinal study on bruxism and TMD prevalence, same data as 21 Study also on adolescents (not possible to extract data of young adults) Same data presented in 29 Same data presented in 31 and as part of 32 Same data presented as part of 34 Same data presented in 30 and as part of 32 Same data presented in 34 Description of oral jaw behaviors in TMD and bruxers Presentation of a device to measure bruxism Same data presented in 34 Same data presented in 33 and as part of 34 Features of TMD and bruxers vs. TMD and nonbruxers subjects Study on adolescents only Study on adolescents only

Summary of findings of questionnaire/self-report studies (Table 2.2) Twenty-one studies which assessed the relation of TMD with bruxism as diagnosed by means of questionnaires or self-report assessments were identified. These studies’ populations accounted for a total of 32116 subjects (15470 females, 14978 males, 1668 unspecified sex), of whom more than 93% (N=29934) were recruited among general population subjects. The remaining were patients with different TMD symptoms (N=2082) or bruxers (N=100). More than 50% of the studies (N=11/21) based their diagnosis of bruxism on a single item, and diagnostic items were not specified in another 5 studies. The questionnaire/self-report bruxism diagnosis was combined with a similar approach to diagnose TMD in 4 papers, and only 9 out of 21 studies adopted the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD)

60

to establish the

presence of TMD symptoms (axis I diagnoses were adopted in 8 papers and axis II in another one). A control group was included in 7/21 studies and, overall, a good quality of statistical design was warranted, with only 4 studies basing their conclusions on univariate

25

D. Manfredini. The triangle bruxism, pain, and psychosocial factors - 2011

statistical analysis. Only one study was performed longitudinally, with four observation points over a 20-year span 34; all the others were cross-sectional studies assessing the TMDbruxism association at a single observation point. In general, the findings are supportive of an association between self-reported/questionnaire-diagnosed bruxism and TMD symptoms, which were found to be associated in 20/21 studies 20,29,32,34,43-46,48-59, while one study did not retrieve any association 47. In the majority of papers, association was found with myofascial pain or symptoms of muscle disorders, but many studies did not specify TMD symptoms. As a result from a couple of studies

45,46

, myofascial pain patients seem to have more teeth contact than controls over a

24-hour period. The teeth-contacting habit may represent a risk factor for the prolongation of pain.

Table 2.2. Summary of findings from studies with a questionnaire or self-report based diagnosis of bruxism. Legends: F, females; M, males; a.r., age range; m.a., mean age; yrs, years; TMJ, temporomandibular joint; ID, internal derangement; ADDWoR, anterior disk displacement without reduction; MR, magnetic resonance; T1W, T1 weighted; T2W, T2 weighted; Q, questionnaire; JE, joint effusion; C.I., confidence interval; OR, odds ratio; MAP, myoarthropathy; NTC, nonfunctional teeth contact; TCH, teeth contacting habit; HADS, Hospital Anxiety and Depression Scale; CP, chronic pain; CA, clinical assessment; MO, mouth opening; CPI, chronic pain intensity; SR, self-report; GCPS, Graded Chronic Pain Scale; M, myogenous; A, arthrogenous; DD, disk displacement; AAOP, American Academy of Orofacial Pain; MFP, myofascial face pain; SCL-90R, Symptoms Checklist-90R; MP, myofascial pain; PDS, pain-dysfunction syndrome; GHQ, General Health Questionnaire; IBQ, Illness Behavior Questionnaire; SE, sensitivity; SP; specificity; CT, computerized tomography. First author and year

Population

Intervention

Comparison

Outcome

Conclusions

Strength

42 joints RDC/TMD Calibrated examiners (nonspecified procedures)

Costa, 2008 43

42 consecutive patients with TMJ ID and pain (35F, 7M; a.r.18-63 yrs.)

Non-specified bruxism diagnosis Headache diagnosis (history and examination) MR (T1W and T2W) for ID and effusion

N=21 TMJ ID and headache N=21 TMJ ID without headache N=16 TMDand headachefree (11F, 5M; a.r. 26-37 yrs.)

Single radiologist Chi-square or

26

Univariate analysis

Bruxism in headache 71.4% (p